There are three bioluminescent bays (bio-bays) in Puerto Rico. One in the SouthWest – "La Parguera", one on Vieques – "Mosquito Bay", and the one in Fajardo – "La Laguna Grande". Out of all three, Mosquito Bay is the brightest, and La Parguera is the least bright. La Laguna Grande in Fajardo is very bright, and it is convenient to do from San Juan and the main island.

What Is It?

A bio bay is a body of water that contains millions of micro-organisms, called “dinoflagellates”, that glow in the dark for a second when agitated. It is a rare, natural wonder that you can easily experience while visiting Puerto Rico. It is best seen on a dark night, try to go when it is moonless or close to it. It also is best on a warm night (summertime is brighter than wintertime, no rain is better than rainy days). But even on a less than ideal night, the bioluminescence will be visible. It is a fragile environment, that can be destroyed (as was the La Parguera bay) by excessive abuse from motor oil, sewerage, sunscreen and bug repellent.

Who To Use?

The usual way most people visit the Fajardo BioBay is on a kayak. There are many kayak operators that guide tours into the bio-bay. They are all similar except for the snacks at the end and the color of their glo-sticks. They all meet at Las Croabas, which is a small bay with a public boat dock. We, and our guests, have used Kayaking Puerto Rico and Las Tortugas in the past – they seem to limit the number of people on their tour and we found them to be very responsive to inquires.

Can I Do It?

We think kayaking is fun and relatively easy. Even if you have never done it before, are out of shape, are young or older – you may want to try it. All the kayak operators provide a mandatory life jacket to wear and will give you a brief “lesson” on how to kayak – and away you go! If you are really bad at it (or just feel uncomfortable) – the group leader usually will help you out. We found the kayaking in the canal isn’t hard except for two places where the canal gets thin, so the current picks up. Some people do go astray and their kayak meets the mangrove bushes, but we didn’t find it to be that big of a problem. We always easily get back on track.

The Details

There are usually 2 trips per night: one right at sundown and one about 8:00-8:30pm. They will ask you get there about 30 mins earlier. Each trip takes about 2.5 hours from start to finish. I like the earlier one because at that time you can still see the iguanas in the trees above you, and it is not so dark on your way through the channel, but it is dark by the time you get to the lagoon.

All the tours start off near the boat ramp, and then you kayak across the boat marina to a thin channel that leads to the lagoon. You have to go single file to avoid hitting each other and the sides of the channel. The mangrove trees make a canopy over your head, which is low in some spots. But as you get closer to the lagoon, you will notice little sparkles as you dip your paddles into the water.

Once you get through the channel, it opens up to a large lagoon. By now, your paddles leave a swirl of glow behind at each stroke. Your tour guide will gather all of the kayaks on your tour together, explain the bioluminescence phenomenon, and answer questions that you might have.

After spending some time playing with the water making sparkles, the guide leads you back through the channel. You may meet up with another group, but if everyone sticks to the right and it all works out. The guides are all bi-lingual, and knowledgeable about the area, the bio-bay and kayaking. They will answer your questions and may even suggest places for dinner after your workout!

Effective in April 2007, the Puerto Rico Department of Natural Resources no longer allows companies operating tours to swim in the lagoon. Though some rogue operators may allow it, be advised that, if the authorities see you swimming, there can be heavy fines levied against the tour operator.

We went again a few years later re-visited Laguna Grande in Fajardo and were happy to find that the ban on swimming has had a positive effect on the health (brightness) of the bio bay.

What To Wear?

All of the kayak operators use sit-upon ocean kayaks, which means that your butt will get wet – wear a bathing suit or shorts that you don’t mind getting wet. Also, getting in and out of the kayak requires you to walk in the water (usually no more than mid-calf deep), so wear water shoes or go bare foot. There is really no where to change at Las Croabas, so wear shorts that will dry quickly, or be prepared to change in your car afterward. Bring a towel or something dry, so that when you get back to shore, you can dry your bottom off.

Most kayak companies run their tours Monday through Saturday, and give the lagoon the night off on Sunday to rest. Some companies do go out on Sundays.

The public bathrooms near the boat ramp are in bad maintenance, so plan accordingly. If you buy a drink at an area restaurant, you can use their bathrooms.

The minimum age to kayak is 6 years old.

Even if an operator has a web site, we recommend calling. Emails often go unanswered.

Prices vary by operator, but are typically around $45-$68 per person. There is a 7% sales tax, which may or may not be included in price.

If you're happy, let them know it — Don't forget to tip your your bartender, tour guide or trip operator if you enjoyed yourself. Gratuities are appreciated and typically aren't included in the price they charge you.

The times for tours vary by operator, but they typically start around sundown, with a second tour around 9:00pm.

Allow at least 2.5 hours for your tour. Check with your tour operator if you’re on a tight schedule.

IO PR Eco-Tours/The Kayak Rental — They go 6 days a week, including Sundays! Glass Bottom Kayaks. 787-616-9594 or (787) 613- 3928 or email them at ioprecotour@gmail.com They can arrange transportation.

The Las Cabezas Nature Reserve also offers a kayak trip into the biobay, but it is only offered in Spanish and one tour on Saturdays only and you must have reservations. For reservations , use their online reservation system. Go to their website http://www.fideicomiso.org/

There are other options for those who cannot kayak:

There are now 2 electric motorboat companies that is allowed to take people into the Laguna Grande BioBay. We think this is a great option for older folks, smaller children and handicapped people (or anyone else who doesn’t want to kayak!). Refer to our review of the trip. Space is limited. One operator goes out on Sundays.

Las Cabezas Nature Reserve has a night tour. An educational tour that also lets you see and play with the bio-luminescent water without too much physical effort. Reasonably priced, it seems ideal for the elderly, handicapped or people with small children, where kayaking or the trip to the Vieques BioBay is not an option. Only available on Thursday – Saturday. Refer to our review for more information, including hours and pricing.

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Thanks for your informative, accurate information. My wife and I used it to set up a Fajardo (Laguna Grande) kayak tour with Las Tortugas in early April, 2009, and we found your description spot-on! We’ve been paddling and diving for decades, and we were blown away by how fun this was. The Las Tortugas group was small, (only 4 boats plus the guide, on the night we went out) the guide was very good, the price was as-advertised, the boats and gear were typical rental quality…and the hyper-bioluminescent location was MAGICAL!

Thanks for helping us have this wonderful experience while we visited Puerto Rico. We also enjoyed the radio telescope at Aricebo and the El Yunque rainforest very,very much! This was all a great warm-up for a week diving on the liveaboard dive boat “Nekton Pilot” that departs seasonally from Fajardo on an itinerary that takes divers to the coast of St. Croix.

Thanks for a ton of great info. I just have a quick question. Not having done kayaking before I’m slightly apprehensive of the water level in the biobays. Are they really deep i.e would we venture too far into the ocean?

When going to the Fajardo biobay, you not really venturing out into the ocean.
You start on the beach and paddle across an area where small boats are moored until you reach the mouth of the channel that goes through the mangroves into the biobay.

I believe the channel is only about 5 or 6 feet deep, while the center of the lagoon (biobay) is around 10 or 12 feet deep.

You’re not paddling in “open water” or doing an “ocean crossing” or anything like that. Actually, it’s more like kayaking in a lake than in the ocean (we have done both).

Our experience with Kayaking Puerto Rico was excellent last year. I have been to La Parguera many times, and even though it has been fun to hang out there, I can tell you that looking at “something” in a bucket is not an experience. Laguna Grande was so amazing and Kayaking Puerto Rico such a great service, that kayaking at the bio-bay in Fajardo is the first thing I tell people about when they ask about what to do in Puerto Rico. I had been on a kayak once before, but even if I hadn’t, the quick lesson we were given and the great attention by the guys of Kayaking Puerto Rico made it very easy and an enjoyable experience. We felt safe at all times and definitely taken care of. Groups with other companies seemed disorganized and even left people behind!! Our guys were SO nice that they helped them get back to their own groups! Expect to definitely get wet from the waist down at least. Make sure you don’t bring any wallets or unnecesary stuff with you. They do have a little box where you can put your car keys and other small items for safeguard, but I had better peace of mind leaving my things in the car (except the car keys of course!). Since the tour is done at nighttime, don’t even bring your camera. The glow cannot be photographed and you’ll just be worried about getting your camera wet the entire time. At the end, they also take a photo of you coming back to shore… which you can purchase. ABSOLUTELY MUST DO WHILE IN P.R.!

I just returned from PR with my teenager. Although I had been to PR dozens of times I had never been to Bio Bay (Fajardo). It was absolutely magical, a must see! We did not kayak, instead we took a small flat bottom boat. The owner, captain, was extremely pleasant and knowledgeable.The boat takes only about 6 passengers. Although those kayaking seemed to be enjoying themselves, by taking the boat we were dry and stayed out longer, The captain also knew where we should look to find iguanas sleeping in trees and other fascinating creatures. Every part of the excursion was incredible, traveling thru the canal felt like a journey thru the amazon, the iridescence of the sea life,and the beautifully starlit night sky was an experience my child and I will always remember. It is not necessary to book this in advance, we decided last minute. The cost was $45 per person.(worth every penny). Unfortunately photos don’t capture the experience since it is at night but you’ll have a lifetime of great memories!

I have been going to the Bioluminescent bay every 5 years or so for a long time. Since the last time you can tell the decrease in bioluminescence. There are several groups that will take you there either via boat or Kayak (we did the Kayak tour). Unfortunately we reserved late therefore we ended up going with a group called Eco Tour since the others were full.The main guide was a young kid who wanted to make more jokes than provide useful info., and one of his assistants was rude and very disrespectful to my wife. Terrible experience due to the Eco Tour guides, and due to the incredible amount of people going at the same time. The channel to get there is not that big and you have to be getting out of the way of boats and other kayak tours. Still we love kayaks and the bay even though it is not the same. Make sure you go either on Boat or Kayak with the Marine Biologist guide in another group. AVOID ECO ACTION TOURS- not very professionals.

I will be arriving in Puerto Rico on 7/31/12 and leaving 8/4/12. I will be staying at the InterContinental San Juan. Please send me any details regarding the Biobay Kayak tours during that time. I would like to book 2 tickets as soon as possible.

Do any of the tour operators have glass-bottom kayaks? My sister and brother-in-law went a couple years ago and she said there were definitely operators that had glass-bottom kayaks which would make the experience even better!

We took a biobay excursion to Laguna Grande with Yokahu. They were really friendly and knowledgable about the bay and the ecosystem. They usually allow children 6 and up, but I definitely would not take a child under 12-14 years. It would be hard or scary for the smaller children to paddle through the dark channel. Once we got to the lagoon, it was amazing. I definitely recommend this to anyone who is going to Puerto Rico. It was very bright and beautiful.

Just got back from PR and took a last minute BioBay trip after visiting Rio Camuy Caves and Arecibo. We were not organized but we were on that side of the island so decided to head to La Parguera. Paid $8 for a 7:45 launch time….ended up being 8:05 but keep in mind you are on their schedule. There were 18 of us and we went out in a motor boat in the bay where the son of the skipper jumped in “for tips”. Unfortunately for him half of the boat went swimming as well, and unfortunately for them this was not a healthy bay at all. The luminescence wasn’t all that bright, the water smelled and like others say, you get what you pay for. The operators were nice, but you can tell that this tourist attraction has affected the beauty of this phenomenon. We were back in an hour so if you are in a hurry, well, make your own decision.

we just returned home from PR and wanted to give a review of our experience. We saw NOTHING. When we asked why we were told that the bio bay is mostly seasonal and winter is not the season. What a huge disapointment especially since it was the reason we chose PR for our vacation. It would be helpful to let visitors know that it not noticeable in parts of the year

Winter time, due to the cooler temps and more frequent rain, there is less visibility. But it should not be “nothing”. We talked with our friends who run a tour and their guides rate the bay’s brightness after every trip. They have said it is running about 60% of it’s brightest summer experience. But according to them, that is totally normal for this time of year. One has to realize that the Fajardo bay sparkles, and people should not expect the electric blue glow as seen on some ads. But it is a shame you didn’t get the full effect. It is pretty cool to see. But I will add more detailed info that the effect is less visible in cooler weather. Thanks!

Just to let others know- we did a kayaking tour of Laguna Grande in early March 2014, and we were able to see quite a bit of luminescence. Of course, nothing as bright as the (Photoshopped) photos the tour groups post in their ads, but definitely a notable blue-green glow with movement and lots of sparkles when you splashed water onto yourself or into the kayak. We went during a new moon, which likely helped and I don’t think it had rained in the area for at least a few days. It was amazing! Something I will never forget, even though we were unable to take any pictures of it.

We did the Fajardo bay in early April with IO tours. There are three key things which will impact your experience:
1. Day: Go on a Sunday when there are only a few tours and you will not bump into other kayaks
2. Moon: Go as close as possible to a new moon
3. Tides: Go for low tides as the glow is better

A while back I remember reading that the biobay in Vieques was the brightest, the Fajardo biobay second brightest, and the one in La Parguera the least bright. Some time later I read that the Fajardo one had gained health/strength, as was comparable to Vieques. After the recent scare with the one in Fajardo, where do you think it stands now? I will be in PR towards the end of June, and wanted to share the experience with my boys and was trying to gauge the current state of the one in Fajardo vs the extra cost, time, and effort of doing the one in Vieques.

Sadly, the Vieques biobay has been having some serious issues this year, and they are now trying to give it a rest by reducing tours. Hopefully it will recover. So in the mean time, the Fajardo Biobay is your best choice.

I have 5 people in my family……2 adults and 3 children ages 16,14,11. We need a kayak tour that provides kayaks for 3 or 1 being as we are an odd number. I would like to have my 11 year old in the same Kayak as me and my husband. Are there accomodations for 5?

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PuertoRicoDayTrips.com assumes no responsibility regarding your safety when participating in the activities described in this article.